In "Lord of the Flies", chapter 11, what's the signisicant of the tittle (Castle Rock) ?

Castle Rock is so named by Jack's group because it is a large outcropping of rock attached to the rest of the island by a narrow rock bridge. It was immediately recognized as a good place for a fortress because it is so easily defended due to its physical structure. Standing on the plateau that is at the top of Castle Rock, one can see anyone approaching on the rock bridge. In chapter 11, Piggy, indignant and frustrated because in the previous chapter, the boys from Jack's tribe stole his glasses, says that he is going to take the conch shell to Jack and try to reason with him. The conch shell, to Piggy only, represents order and reason. To everyone else, it has ceased to have any meaning indicating that order and reason are all but gone. When Piggy does as he said he would and he goes to Jack with the shell, it is to Castle Rock that he goes. Castle Rock, being Jack's fortress, represents savagery. Essentially then, the last vestiges of reason come to the heart of savagery and savagery wins. When Piggy goes to Castle Rock, he is killed there when Roger drops the boulder from the top of Castle Rock onto Piggy's head, crushing him and the conch shell. The killing of Piggy and the crushing of the conch represent the end of all order and reason. Castle Rock, or savagery, reigns supreme.